The Good:
All of the things mentioned that reduce maintenance and simplify the hobby (2.4g, BL Motors, LiPo, Personal Transponders.
The Bad:
Things that complicate the hobby and make the learning curve steeper so new racers have a hard time getting up to speed.
The complexity of sedans, learning what the adjustments do, how setup changes have to compliment each other to get what you want.
Timing Boost. Sure you can get a setup from the local fast guy but big track changes or racing at different tracks make little tweaks necessary to get the fastest most consistent handling car. It is very complicated for a new racer to understand how to set their speedo for boosted racing.
Too many classes. It seems every track has its own rules. 1/12th stock can be 17.5 boosted or blink or 13.5 blinky. Most sedan racing is 17.5 or 13.5 blinky at club racers, VTA is all over the place track to track. It used to be everyone agreed to follow the ROAR rules even if they were not a ROAR track. I think we need to get back to more pure compliance/interpretations of the rules.